This proposal represents a request for funds to purchase an Andor Revolution XD Spinning Disk Confocal System on a Nikon Perfect Focus TIRF Microscope from a group of PHS funded investigators having overlapping imaging needs. The system will be housed in the Department of Biological Sciences'Shared Imaging Facility, which is operated by the Molecular Biosensor and Imaging Center (MBIC) as a multi-user facility in the Mellon College of Science at Carnegie Mellon University. MBIC is currently funded as one of only five National Technology Centers for Networks and Pathways. Its core mission is to develop optical biosensor and imaging informatics technologies for the detection of molecular-level interactions within living cells and biological tissues. The acquisition of the proposed instrument will provide on-site access to state of the art high-speed multi- color confocal and TIRF microscopy instrumentation within the Mellon Institute, which is essential for a variety of live cell and membrane trafficking experiments, as well as for routine analysis and characterization of the fluorescent probe technology developed within MBIC. Instruments that are currently available within MBIC and partner faculty's research laboratories are both aged and unsupported or currently fully utilized. While access to other advanced microscopy instrumentation is possible within the general Pittsburgh area, we have found that this poses a logistical problem for experiments using living cells and developing embryos and is not practical for experiments of this kind. In addition, the capabilities of the proposed system meets a number of current needs that existing instrumentation is incapable of fulfilling. Since MBIC is a multi-disciplinary collaborative center which brings together a diverse collection of Carnegie Mellon faculty spanning several academic departments, colleges and research institutes, the acquired instrument will provide investigators across the university with substantially improved imaging capabilities to integrate into their research programs and will provide new opportunities to address fundamental biological questions using advanced microscopy and imaging methodologies.